Printing plate and process of producing the same



Sept 16, 1930- A. E. VILLAREJO -1,776,015

PRINTING PLATE AND PROCESS OF PRODUCING THE SAMEy Filed Oct. 21, 1929Patented Sept. 16, 1930` UNITED STATES PATENT OFFICE ALFRED EQ.'VILLAREJ'O, OF MILWAUKEE, WISCONSIN, ASSIGNOR 0F ONE-HALF TO RUDOLF PZETTINIG, 0F MILWAUKEE, WISCONSIN PRINTING PLATE AND PROCESS OFPRODUCING THE SAME Application led October 421, 1929. Serial No.401,032.

This invention relates in general to the production of printing platesby electrodeposition and more particularly ,to the direct production ofsuch plates on a metallic a original.

In applying graining, simulating Wood graining, or otherornamentationto'the metal panels of automobile bodies, it is the usualpractice to have a positive metal plate or 1o original on which thegraining or design has been produced. In the case of Wood graining, theoriginal metal plate has ridges and valleys, conforming to the contourof the graining. The plate is inked and after any i5 excess of the inkis removed, a roller is run over the plate and then run over the metalpanel of the automobile body so that the-design is transferred to themetal panel of the automobile body.

The production of the positive metal plates from which the impressionsare transferred by the roller is a source of difficulty and ex pense,especially Where these plates are of any substantial size, as theyfrequently must be in connection with the graining of, or theapplication of other ornamentation to, certain automobile panels.

In this art the practice heretofore has been to produce a design on theoriginal metal plate by a photographic (half-tone) process, and thentransfer the impression or design from the original to a body of Wax bypressing the body of Wax against the original. The surface of the Waxwhich has the impression produced thereon in this Way is then coatedwith graphite and then placed in an electro-plating bath and subjectedto the electro-plating process so. that a coating of copper is thendeposited over the graphite surface of the Wax. The Wax is then meltedout of the deposited plate and this plate is the one thatl is inked andfrom Which the impression is transferred to the automobile panel by Ithetransferring roller.

One of the principal objects of the present invention is to dispensewith the use of the Wax and to deposit the metal in the electroplatingbath, directly onto the original metal plate produced by the usualphotographic process. The great difficulty that has here-'unsatisfactory for various reasons such as expense, loss of detail,damage -to theoriginal or the like.

The present invention produces a separating or stripping film on theoriginal in a speedy and comparatively inexpensive manner and does thisWithout damage to the original and Without loss of detail and yetinsures the easy stripping olf of the electrolytically deposited plate.

Other objects and advantages reside in certain novel features which Willbe hereinafter more fully described, and particularly pointed out in theappended claims, reference being had -to the accompanying drawingforming a part of this specification and in which:

Figure l is a plan View of an original from which printing plates are tobe produced;

Figure 2 is a View in section of line 2-2 of Figure l;

Figure 3 is a figure similar to Figure 2, but illustrating the coatingformed on the surface of the original plate which carries the design,the coating being exaggerated for the sake of clearness;

Figure 4 is a diagrammatic vieW` illustrating hovv the negative plate isdeposited on the original;

Figure 5 is a vieW similar to Figure 3, showing how the positiveprinting plate is deposited on the negative plate; and

Figure 6 is a diagrammatic view in perspective illustrating how theinked roller is used with the positive printing plate prod ueed inaccordance With the present invention.

Referring then to the drawings, it will be seen that an original metalplate l, preferably of copper, is provided and has a design etched orotherwise formed on the surface 2 thereof bymeans of a conventionalphotographic process. The surface 2, on which the design is formed orcarried, is first subjected to a bath of ammonium polysulphide (NHQgSa,either by immersing the surface 2 in a concentrated solution of ammoniumpolysulphide or by subjecting it toa light washing therewith, the latterbeing preferred. The ammonium polysulphide reacts with the copper of thesurface 2 of the plate l to produce a very light film or coating ofcopper sulphide on the surface of the original copper plate carrying thedesign. After the treatment with the ammonium polysulphide, the plate isdried-atmospheric drying being sufficientand is thenwashed gently withdistilled water. Following this the plate is baked to harden the thinfilm of copper sulphide produced thereon by the ammonium polysu'lphide.

The plate, thus prepared, is placed in an ordinary'electro-plating bathas illustrated diagrammatically in Figure 4 and a shell of copper isdeposited thereon in the ordinary way, When sufficient metalhas beendeposv ited to make the shell 3 of the desired thick- Y ness, the plateand shell are removed from the bath and the shell 3 is stripped from theoriginal plate 1. The shell will come olf easily due to the use of thesulphide coating on the original plate. The shell 3 is, however, anegative. In order to produce a positive from the shell 3 theprocess isrepeated and is identical with the process above described, except thatthe thin shell 3 must be placed on an appropriate backing shown at 5 inFigure 5 unless it is made sufliciently heavy to dispense with thebacking. The shell 3 is, however, treated with -ammonium polysulphideto-produce the thin coating or film of copper sulphide thereon and isthen dried, washed, baked and put in an electro-plating bath asillustrated inFigure 5 so that the positive printing plate, or shell 4,is deposited on the shell 3. rlhis shell 4 can also be easily strippedfrom the shell 3, and may be later usedl as indicated in Figure 6, tovapply the impression to the transferring roller 6 which in turn appliesthe impression to the panel to be ornamented.

As indicated, ammonium polysulphide is preferably the reagent used toproduce the copper sulphide coating as it produces a hard film that willnot flake off and that will not impair the design. However, otherreagents such as potassium sulphide `or sodium sulphide may be employedto produce the coatmg.

It is to be noted that the copper sulphide coating is formed on and ofthe metal which constitutes the features of the original design and isan integral part of such features. In other words, the copper sulphidecoating is a result of the transformation of the surface metal of thecopper plate and consequentl there is no-loss in detail in the design onsuoli surface. It is coherent .and will not rub off or be. displaced andas it is a constituent part of the features of the desi n and is ofuniform thickness it does not eprive the design of any of its detail,nor does it impair the same in any Way. Further, the

film is a good conductor of electricity so as skill.

The invention claimed is:

1. The herein described process of producing printing plates from anoriginal copper plate which consists in first, subjecting the surface ofthe original copper plate carrying the design to a bath of ammoniumpolysulphide to form a thin film of copper sulphide on and as a part ofthe metal of the plate that constitutes the features of the design,drying and washing the original plate,

baking the original plate to harden the film thereon, thenelectrodepositing a negative copper plate on the film 'coated original,stripping of the ne ative plate from the original,sim1larly coatlng thesurface of the negative plate with copper sulphide, and finallyelectro-depositing a positive printing plate on the film coated surfaceof the negative plate.

2. The herein described process of producing printing plates from anoriginal copper plate which consists in first, subjecting the surface ofthe original copper plate carrying the design to a bath of ammoniumpolysulphide to form a thin film of copper'sulphide thereon and as apart of the metal of the plate vthat constitutes the features of thedesign drying and washing the original plate, an baking the originalplate to harden the design thereon.

In witness whereof, I hereto alx my signature.

ALFRED E. VILLAREJO.

